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There are several studies proposing phenomenological consequences of a deformation of special and general relativity. Here, we cast novel constraints on the deformation parameter of a metric in the cotangent bundle accounting for a curved…

General Relativity and Quantum Cosmology · Physics 2020-11-18 J. J. Relancio , S. Liberati

The universe with adiabatic matter creation is considered. It is thought that the negative pressure caused by matter creation can play the role of a dark energy component, and drive the accelerating expansion of the universe. Using the Type…

Astrophysics · Physics 2015-06-24 Yuan Qiang , Tong-Jie Zhang , Ze-Long Yi

The predictions of the inflationary LCDM paradigm match today's high-precision measurements of the cosmic microwave background anisotropy extremely well. The same data put tight limits on other sources of anisotropy. Cosmic strings are a…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-29 Cora Dvorkin , Mark Wyman , Wayne Hu

The presence of a significant amount of gravitational radiation in the early Universe affects the total energy density and hence the expansion rate in the early epoch. In this work, we develop a physical model to connect the parameter of…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-08 Moumita Aich , Yin-Zhe Ma , Wei-Ming Dai , Jun-Qing Xia

It is commonly assumed that the stochastic background of gravitational waves on cosmological scales follows an almost scale-independent power spectrum, as generically predicted by the inflationary paradigm. However, it is not inconceivable…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-14 Jan Hamann , Ameek Malhotra

Motivated by the string gas cosmological model, which predicts a blue tilt of the primordial gravitational wave spectrum, we examine the constraints imposed by current and planned observations on a blue tilted tensor spectrum. Starting from…

Astrophysics · Physics 2009-06-23 Andrew Stewart , Robert Brandenberger

Different inflationary models predict oscillatory features in the primordial power spectrum. These can leave an imprint on both the cosmic microwave background (CMB) and the large-scale structure (LSS) of our Universe, that can be searched…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-15 Chenxiao Zeng , Ely D. Kovetz , Xuelei Chen , Yan Gong , Julian B. Muñoz , Marc Kamionkowski

Using the covariant formalism developed in a companion paper (paper I), we derive observational constraint on the Brans-Dicke model in a flat FLRW universe with cosmological constant and cold dark matter. The CMB observations we use include…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-18 Fengquan Wu , Xuelei Chen

If the Universe is open, scales larger than the curvature scale may be probed by large-angle fluctuations in the cosmic microwave background (CMB). We consider primordial adiabatic perturbations and discuss power spectra that are power laws…

Astrophysics · Physics 2008-11-26 Marc Kamionkowski , David N. Spergel

We try to constrain the noncommutativity length scale of the theoretical model given in Ref. [1] using the observational data from ACBAR, CBI and five year WMAP. The noncommutativity parameter is not constrained by WMAP data, however ACBAR…

An analysis of cosmological mixed dark matter models in spatially flat Friedmann Universe with zero $\Lambda$-term is presented. We argue that the introduction of cosmic gravity waves helps to satisfy observational constraints. The analysis…

Astrophysics · Physics 2007-05-23 E. V. Mikheeva

Measurements of the cosmic microwave background (CMB) temperature anisotropies have revealed a dipolar asymmetry in power at the largest scales, in apparent contradiction with the statistical isotropy of standard cosmological models. The…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-07 D. Contreras , J. Hutchinson , A. Moss , D. Scott , J. P. Zibin

The recent measurements of temperature and polarization of Cosmic Microwave Background (CMB) have improved our understanding of the Universe and are in remarkable agreement with the $\Lambda$CDM cosmological model. However, scale dependent…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-15 Suvodip Mukherjee , Tarun Souradeep

We revisit the constraints on inflation models by using the current cosmological observations involving the latest local measurement of the Hubble constant ($H_{0} = 73.00\pm 1.75$ km s $^{-1}$ Mpc$^{-1}$). We constrain the primordial power…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-20 Rui-Yun Guo , Xin Zhang

Recent data, including the three--year WMAP data, the full 2dF galaxy power spectrum and the first--year data of the Supernova Legacy Survey, are used to constrain model parameters in quintessence cosmologies. In particular, we discuss the…

Astrophysics · Physics 2009-11-11 L. P. L. Colombo , M. Gervasi

We combine COBE-DMR measurements of cosmic microwave background anisotropy with a recent measurement of the mass power spectrum at redshift z=2.5 from Lya forest data to derive constraints on cosmological parameters and test the…

Soft cosmology is an extension of standard cosmology allowing for a scale-dependent equation-of-state (EoS) parameter in the dark sectors, which is one of the properties of soft materials in condensed-matter physics, that may arise either…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-12 Emmanuel N. Saridakis , Weiqiang Yang , Supriya Pan , Fotios K. Anagnostopoulos , Spyros Basilakos

Recent high precision data by WMAP and SDSS have provided strong evidence to suggest that the universe is nearly flat. They are also making it possible to probe the topology of the universe. Motivated by these results, we have recently…

Astrophysics · Physics 2009-11-10 B. Mota , M. J. Reboucas , R. Tavakol

We review a subset of the current tensions affecting the standard $\Lambda$CDM cosmological model, emphasizing the role of chronic systematics and significance inflation in shaping their interpretation. As a unifying framework, we consider…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-02 Valerio Marra

The formation of structure in the Universe offers some of the most powerful evidence in favour of the existence of dark matter in the Universe. We summarize recent work by ourselves and our collaborators, using linear and quasi-linear…

Astrophysics · Physics 2007-05-23 Andrew R Liddle , Pedro T P Viana
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